<s>
A	O
system	B-Application
file	I-Application
in	O
computers	O
is	O
a	O
critical	O
computer	B-Operating_System
file	I-Operating_System
without	O
which	O
a	O
computer	O
system	O
may	O
not	O
operate	O
correctly	O
.	O
</s>
<s>
These	O
files	O
may	O
come	O
as	O
part	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
a	O
third-party	O
device	B-Application
driver	I-Application
or	O
other	O
sources	O
.	O
</s>
<s>
Microsoft	B-Application
Windows	I-Application
and	O
MS-DOS	B-Application
mark	O
their	O
more	O
valuable	O
system	B-Application
files	I-Application
with	O
a	O
"	O
system	O
"	O
attribute	B-General_Concept
to	O
protect	O
them	O
against	O
accidental	O
deletion	O
.	O
</s>
<s>
(	O
Although	O
the	O
system	O
attribute	B-General_Concept
can	O
be	O
manually	O
put	O
on	O
any	O
arbitrary	O
file	O
;	O
these	O
files	O
do	O
not	O
become	O
system	B-Application
files	I-Application
.	O
)	O
</s>
<s>
Specific	O
example	O
of	O
system	B-Application
files	I-Application
include	O
the	O
files	O
with	O
.sys	O
filename	O
extension	O
in	O
MS-DOS	B-Application
.	O
</s>
<s>
In	O
Windows	B-Device
NT	I-Device
family	I-Device
,	O
the	O
system	B-Application
files	I-Application
are	O
mainly	O
under	O
the	O
folder	O
C:\Windows\System32	O
.	O
</s>
<s>
In	O
Mac	B-Application
OS	I-Application
they	O
are	O
in	O
the	O
System	B-Application
suitcase	I-Application
.	O
</s>
<s>
And	O
in	O
Linux	B-Application
system	O
the	O
system	B-Application
files	I-Application
are	O
located	O
under	O
folders	O
/boot	O
(	O
the	O
kernel	B-Operating_System
itself	O
)	O
,	O
/usr/sbin	O
(	O
system	B-Application
utilities	I-Application
)	O
and	O
/usr/lib/modules	O
(	O
kernel	B-Operating_System
device	B-Application
drivers	I-Application
)	O
.	O
</s>
